Samsung FTQ353IWUB Service Manual page 41

4. Troubleshooting
4- Electrical Malfunction
* Measure resistance and voltage
of Low voltage Transformer
(please refer to Fig.1)
Low Voltage Transformer Low Voltage Transformer
*Check whether primary resistance of
Low voltage Transformer is in normal.
*Measure voltage of voltage Regulator
on main PCB.
IC02(7812) : DC 12V
IC03(7805) : DC 5V
* replace Main PCB.
END
Input 120V Input 120V
Yes
Yes
Fig.1 : Low voltage Transformer
No voltage
Primary 120V
(input)
Secondary 1 13.5V
Secondary 2 7V
*Thermal Fuse with built-in Low voltage
No
Transformer will be open if resistance is
more than MΩ.
* Replace Low Voltage Transformer
END
41
resistance
110 ~ 120Ω
1.5 ~ 2.5
1.7 ~ 2.0
Ye s